Adherent device with multiple physiological sensors

ABSTRACT

An adherent device to monitor a patient for an extended period comprises a breathable tape. The breathable tape comprises a porous material with an adhesive coating to adhere the breathable tape to a skin of the patient. At least one electrode is affixed to the breathable tape and capable of electrically coupling to a skin of the patient. A printed circuit board is connected to the breathable tape to support the printed circuit board with the breathable tape when the tape is adhered to the patient. Electronic components electrically are connected to the printed circuit board and coupled to the at least one electrode to measure physiologic signals of the patient. A breathable cover and/or an electronics housing is disposed over the circuit board and electronic components and connected to at least one of the electronics components, the printed circuit board or the breathable tape.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation of pending U.S. patentapplication Ser. No. 13/347,238 filed Jan. 10, 2012 and titled “AdherentDevice with Multiple Physiological Sensors” which is a continuation ofU.S. patent application Ser. No. 12/209,273 filed Sep. 12, 2008 andtitled “Adherent Device with Multiple Physiological Sensors”, now U.S.Pat. No. 8,116,841, which claims the benefit under 35 USC 119(e) of U.S.Provisional Application Nos. 60/972,629 and 60/972,537 both filed Sep.14, 2007, and 61/055,645 and 61/055,666 both filed May 23, 2008; thefull disclosures of all of which are incorporated herein by reference intheir entirety.

The subject matter of the present application is related to thefollowing applications: 60/972,512; 60/972,329; 60/972,354; 60/972,616;60/972,363; 60/972,343; 60/972,581; 60/972,316; 60/972,333; 60/972,359;60/972,336; 60/972,340 all of which were filed on Sep. 14, 2007;61/046,196 filed Apr. 18, 2008; 61/047,875 filed Apr. 25, 2008;61/055,656 and 61/055,662 both filed May 23, 2008; and 61/079,746 filedJul. 10, 2008.

The following applications were filed concurrently with the parent ofthe present application, on Sep. 12, 2008: U.S. application Ser. No.12/209,279 entitled “Multi-Sensor Patient Monitor to Detect ImpendingCardiac Decompensation Prediction”; 026843-000220US entitled “AdherentDevice with Multiple Physiological Sensors”; 026843-000410US entitled“Injectable Device for Physiological Monitoring”; 026843-000510USentitled “Delivery System for Injectable Physiological MonitoringSystem”; 026843-000620US entitled “Adherent Device for Cardiac RhythmManagement”; 026843-000710US entitled “Adherent Device for RespiratoryMonitoring”; 026843-000810US entitled “Adherent Athletic Monitor”;026843-000910US entitled “Adherent Emergency Monitor”; 026843-001410USentitled “Medical Device Automatic Start-up upon Contact to PatientTissue”; 026843-001900US entitled “System and Methods for Wireless BodyFluid Monitoring”; 026843-002010US entitled “Adherent Cardiac Monitorwith Advanced Sensing Capabilities”; 026843-002410US entitled “AdherentDevice for Sleep Disordered Breathing”; 026843-002710US entitled“Dynamic Pairing of Patients to Data Collection Gateways”;026843-003010US entitled “Adherent Multi-Sensor Device with ImplantableDevice Communications Capabilities”; 026843-003110US entitled “DataCollection in a Multi-Sensor Patient Monitor”; 026843-003210US entitled“Adherent Multi-Sensor Device with Empathic Monitoring”; 026843-003310USentitled “Energy Management for Adherent Patient Monitor”; and026843-003410US entitled “Tracking and Security for Adherent PatientMonitor.”

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to patient monitoring and/or therapy.Although embodiments make specific reference to monitoring impedance andelectrocardiogram signals with an adherent device, the system methodsand devices described herein may be applicable to many applications inwhich physiological monitoring and/or therapy is used for extendedperiods, for example wireless physiological monitoring for extendedperiods.

Patients are often treated for diseases and/or conditions associatedwith a compromised status of the patient, for example a compromisedphysiologic status. In some instances, a patient may report symptomsthat require diagnosis to determine the underlying cause. For example, apatient may report fainting or dizziness that requires diagnosis, inwhich long term monitoring of the patient can provide useful informationas to the physiologic status of the patient. In some instances a patientmay have suffered a heart attack and require care and/or monitoringafter release from the hospital. One example of a device to provide longterm monitoring of a patient is the Holter monitor, or ambulatoryelectrocardiography device.

In addition to measuring heart signals with electrocardiograms, knownphysiologic measurements include impedance measurements. For example,transthoracic impedance measurements can be used to measure hydrationand respiration. Although transthoracic measurements can be useful, suchmeasurements may use electrodes that are positioned across the midlineof the patient, and may be somewhat uncomfortable and/or cumbersome forthe patient to wear. In at least some instances, the electrodes that areheld against the skin of the patient may become detached and/ordehydrated, such that the electrodes must be replaced, thereby makinglong term monitoring more difficult.

Work in relation to embodiments of the present invention suggests thatknown methods and apparatus for long term monitoring of patients may beless than ideal. In at least some instances, devices that are worn bythe patient may be somewhat uncomfortable, which may lead to patientsnot wearing the devices and not complying with direction from the healthcare provider, such that data collected may be less than ideal.

Therefore, a need exists for improved patient monitoring. Ideally, suchimproved patient monitoring would avoid at least some of theshort-comings of the present methods and devices.

2. Description of the Background Art

The following U.S. Patents and Publications may describe relevantbackground art: U.S. Pat. Nos. 3,170,459; 3,370,459; 3,805,769;3,845,757; 3,972,329; 4,121,573; 4,141,366; 4,838,273; 4,955,381;4,981,139; 5,080,099; 5,353,793; 5,511,553; 5,544,661; 5,558,638;5,724,025; 5,772,586; 5,862,802; 6,047,203; 6,117,077; 6,129,744;6,225,901; 6,385,473; 6,416,471; 6,454,707; 6,527,711; 6,527,729;6,551,252; 6,595,927; 6,595,929; 6,605,038; 6,645,153; 6,795,722;6,821,249; 6,980,851; 7,020,508; 7,054,679; 7,153,262; 2003/0092975;2005/0113703; 2005/0131288; 2006/0010090; 2006/0031102; 2006/0089679;2006/122474; 2006/0155183; 2006/0224051; 2006/0264730; 2007/0021678; and2007/0038038.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to patient monitoring. Althoughembodiments make specific reference to monitoring impedance andelectrocardiogram signals with an adherent patch, the system methods anddevice described herein may be applicable to any application in whichphysiological monitoring and/or therapy is used for extended periods,for example wireless physiological monitoring for extended periods. Inmany embodiments, the adherent device comprises a breathable support,for example a breathable adherent patch, and breathable cover that canbe used for extended periods with improved patient comfort. Thebreathable adherent patch, for example breathable tape, and breathablecover may be configured to stretch, for example to stretch togetheralong two dimensions of the skin of the patient when the patch isadhered to the skin of the patient, such that patient comfort and thelifetime of the patch on the skin can be improved.

According to one aspect, an adherent device to monitor a patient for anextended period includes a breathable tape with an adhesive coating toadhere the breathable tape to a skin of the patient, at least oneelectrode affixed to the breathable tape and capable of electricallycoupling to a skin of the patient, and electronic componentselectrically coupled to the at least one electrode to measurephysiologic signals of the patient. The electronic components arecoupled to the breathable tape to support the electronic components whenthe tape is adhered to the patient. The adherent device further includesan electronics housing covering the electronic components, and abreathable cover disposed over the electronic components such that theelectronics housing is disposed between the cover and the electroniccomponents. In some embodiments, the adherent device further includes aprinted circuit board to which the electronic components areelectrically connected. The adherent device may further include aflexible connection structure to couple the electrodes to the printedcircuit board so as to relieve strain between the electrodes and theprinted circuit board. The electronics housing may be adhered to atleast one of the electronic components. The breathable cover may beconnected to the breathable tape. The breathable cover may include astretchable material. In some embodiments, the breathable cover fitsloosely over the electronics housing, such that a portion of thebreathable cover can move with respect to the electronics housing. Theelectronics housing may be smooth, such that the breathable cover isslidably coupled with the electronics housing.

In some embodiments, the electronic components comprise wirelesscommunications circuitry that transmits at least one physiologic signalto a remote server. The electronic components may include impedancecircuitry, wherein the wireless communications circuitry is coupled tothe impedance circuitry to transmit to the remote server a hydrationsignal derived from an output of the impedance circuitry. The electroniccomponents may include electrocardiogram circuitry, wherein the wirelesscommunications circuitry is coupled to the electrocardiogram circuitryto transmit to the remote server an electrocardiogram signal derivedfrom an output of the electrocardiogram circuitry. The electroniccomponents may include an accelerometer, wherein the wirelesscommunications circuitry is coupled to the accelerometer to transmit tothe remote server an inclination signal derived from an output of theaccelerometer.

In some embodiments, the breathable tape comprises an acrylate pressuresensitive adhesive on an underside of the tape, and the adhesive has athickness less than about 0.004″ to allow the tape to breath when theadhesive is applied to the patient. In some embodiments, the electronicshousing comprises a waterproof encapsulant to protect the electroniccomponents from moisture and/or mechanical forces.

In some embodiments, the adherent device includes a gel cover positionedover the breathable tape to inhibit a flow of the gel through thebreathable tape, and the electronic components are located over the gelcover such that the gel cover is disposed between the breathable tapeand the electronic components. The gel cover may include at least one ofa polyurethane film or polyurethane non-woven backing and an acrylatepressure sensitive adhesive. The gel cover may have a porosity of atleast about 200 sec./100 cc/in^2 to protect the hydrogel from externalmoisture. The breathable tape may include a knit polyester fabricbacking and the gel cover may include a polyurethane film backing. Insome embodiments, the breathable tape has a first porosity and the gelcover comprises a breathable tape with a second porosity, the secondporosity less than the first porosity to inhibit flow of the gel throughthe breathable tape having the first porosity.

In some embodiments, the electronic components are comprised in anelectronics module that is separable from the breathable tape, theadhesive coating, and the at least one electrode. The electronics modulemay be reusable. The breathable tape, the adhesive coating, and the atleast one electrode may not be reusable. The electronics module mayinclude the breathable cover. The electronics module may include theelectronics housing.

In some embodiments, the adherent device further includes at least onegel disposed over a contact surface of the at least one electrode toelectrically connect the electrode to the skin. The adherent device mayfurther include an adhesive disposed around the breathable tape toconnect the cover to the breathable tape. The adherent device mayfurther include a gel cover positioned over the breathable tape, whereina moisture vapor transmission rate (MVTR) through the breathable tape,the gel cover, and the breathable cover is at least about 400 g/m²/24hrs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a patient and a monitoring system comprising an adherentdevice, according to embodiments of the present invention;

FIG. 1B shows a bottom view of the adherent device as in FIG. 1Acomprising an adherent patch;

FIG. 1C shows a top view of the adherent patch, as in FIG. 1B;

FIG. 1D shows a printed circuit boards and electronic components overthe adherent patch, as in FIG. 1C;

FIG. 1D1 shows an equivalent circuit that can be used to determineoptimal frequencies for determining patient hydration, according toembodiments of the present invention;

FIG. 1E shows batteries positioned over the printed circuit board andelectronic components as in FIG. 1D;

FIG. 1F shows a top view of an electronics housing and a breathablecover over the batteries, electronic components and printed circuitboard as in FIG. 1E;

FIG. 1G shows a side view of the adherent device as in FIGS. 1A to 1F;

FIG. 1H shown a bottom isometric view of the adherent device as in FIGS.1A to 1G;

FIGS. 1I and 1J show a side cross-sectional view and an exploded view,respectively, of the adherent device as in FIGS. 1A to 1H;

FIGS. 1I1 and 1J1 show a side cross-sectional view and an exploded view,respectively, of an adherent device with a temperature sensor affixed tothe gel cover, according to embodiments of the present invention;

FIG. 1K shows at least one electrode configured to electrically coupleto a skin of the patient through a breathable tape, according toembodiments of the present invention; and

FIGS. 2A and 2B show components of an adherent device comprising anadhesive patch and connection structures to provide strain relief so asto decouple the adhesive patch from an electronics module, according toembodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention relate to patient monitoring and/ortherapy. Although embodiments make specific reference to monitoringimpedance and electrocardiogram signals with an adherent device, thesystem methods and device described herein may be applicable to anyapplication in which physiological monitoring and/or therapy is used forextended periods, for example wireless physiological monitoring forextended periods.

The adherent device comprises a support, for example a patch that maycomprise breathable tape, and the support can be configured to adhere tothe patient and support the electronics and sensors on the patient. Thesupport can be porous and breathable so as to allow water vaportransmission. The support can also stretch with skin of the patient, soas to improve patient comfort and extend the time that the support canbe adhered to the patient.

In many embodiments, the adherent devices described herein may be usedfor 90 day monitoring, or more, and may comprise completely disposablecomponents and/or reusable components, and can provide reliable dataacquisition and transfer. In many embodiments, the patch is configuredfor patient comfort, such that the patch can be worn and/or tolerated bythe patient for extended periods, for example 90 days or more. The patchmay be worn continuously for at least seven days, for example 14 days,and then replaced with another patch. Adherent devices with comfortablepatches that can be worn for extended periods and in which patches canbe replaced and the electronics modules reused are described in U.S.Pat. App. Nos. 60/972,537, entitled “Adherent Device with MultiplePhysiological Sensors”; and 60/972,629, entitled “Adherent Device withMultiple Physiological Sensors”, both filed on Sep. 14, 2007, the fulldisclosures of which have been previously incorporated herein byreference. In many embodiments, the adherent patch comprises a tape,which comprises a material, preferably breathable, with an adhesive,such that trauma to the patient skin can be minimized while the patch isworn for the extended period. The printed circuit board may comprise aflex printed circuit board that can flex with the patient to provideimproved patient comfort.

FIG. 1A shows a patient P and a monitoring system 10. Patient Pcomprises a midline M, a first side S1, for example a right side, and asecond side S2, for example a left side. Monitoring system 10 comprisesan adherent device 100. Adherent device 100 can be adhered to a patientP at many locations, for example thorax T of patient P. In manyembodiments, the adherent device may adhere to one side of the patient,from which side data can be collected. Work in relation with embodimentsof the present invention suggests that location on a side of the patientcan provide comfort for the patient while the device is adhered to thepatient.

Monitoring system 10 includes components to transmit data to a remotecenter 106. Remote center 106 can be located in a different buildingfrom the patient, for example in the same town as the patient, and canbe located as far from the patient as a separate continent from thepatient, for example the patient located on a first continent and theremote center located on a second continent. Adherent device 100 cancommunicate wirelessly to an intermediate device 102, for example with asingle wireless hop from the adherent device on the patient to theintermediate device. Intermediate device 102 can communicate with remotecenter 106 in many ways, for example with an internet connection and/orwith a cellular connection. In many embodiments, monitoring system 10comprises a distributed processing system with at least one processorcomprising a tangible medium on device 100, at least one processor onintermediate device 102, and at least one processor 106P at remotecenter 106, each of which processors can be in electronic communicationwith the other processors. At least one processor 102P comprises atangible medium 102T, and at least one processor 106P comprises atangible medium 106T. Remote processor 106P may comprise a backendserver located at the remote center. Remote center 106 can be incommunication with a health care provider 108A with a communicationsystem 107A, such as the Internet, an intranet, phone lines, wirelessand/or satellite phone. Health care provider 108A, for example a familymember, can be in communication with patient P with a communication, forexample with a two way communication system, as indicated by arrow 109A,for example by cell phone, email, landline. Remote center 106 can be incommunication with a health care professional, for example a physician108B, with a communication system 107B, such as the Internet, anintranet, phone lines, wireless and/or satellite phone. Physician 108Bcan be in communication with patient P with a communication, for examplewith a two way communication system, as indicated by arrow 109B, forexample by cell phone, email, landline. Remote center 106 can be incommunication with an emergency responder 108C, for example a 911operator and/or paramedic, with a communication system 107C, such as theInternet, an intranet, phone lines, wireless and/or satellite phone.Emergency responder 108C can travel to the patient as indicated by arrow109C. Thus, in many embodiments, monitoring system 10 comprises a closedloop system in which patient care can be monitored and implemented fromthe remote center in response to signals from the adherent device.

In many embodiments, the adherent device may continuously monitorphysiological parameters, communicate wirelessly with a remote center,and provide alerts when necessary. The system may comprise an adherentpatch, which attaches to the patient's thorax and contains sensingelectrodes, battery, memory, logic, and wireless communicationcapabilities. In some embodiments, the patch can communicate with theremote center, via the intermediate device in the patient's home. Insome embodiments, the remote center 106 receives the patient data andapplies a patient evaluation and/or prediction algorithm. When a flag israised, the center may communicate with the patient, hospital, nurse,and/or physician to allow for therapeutic intervention, for example toprevent decompensation.

The adherent device may be affixed and/or adhered to the body in manyways. For example, with at least one of the following an adhesive tape,a constant-force spring, suspenders around shoulders, a screw-inmicroneedle electrode, a pre-shaped electronics module to shape fabricto a thorax, a pinch onto roll of skin, or transcutaneous anchoring.Patch and/or device replacement may occur with a keyed patch (e.g.two-part patch), an outline or anatomical mark, a low-adhesive guide(place guide|remove old patch|place new patch|remove guide), or a keyedattachment for chatter reduction. The patch and/or device may comprisean adhesiveless embodiment (e.g. chest strap), and/or a low-irritationadhesive for sensitive skin. The adherent patch and/or device cancomprise many shapes, for example at least one of a dogbone, anhourglass, an oblong, a circular or an oval shape.

In many embodiments, the adherent device may comprise a reusableelectronics module with replaceable patches, and each of the replaceablepatches may include a battery. The module may collect cumulative datafor approximately 90 days and/or the entire adherent component(electronics+patch) may be disposable. In a completely disposableembodiment, a “baton” mechanism may be used for data transfer andretention, for example baton transfer may include baseline information.In some embodiments, the device may have a rechargeable module, and mayuse dual battery and/or electronics modules, wherein one module 101A canbe recharged using a charging station 103 while the other module 101B isplaced on the adherent patch with connectors. In some embodiments, theintermediate device 102 may comprise the charging module, data transfer,storage and/or transmission, such that one of the electronics modulescan be placed in the intermediate device for charging and/or datatransfer while the other electronics module is worn by the patient.

System 10 can perform the following functions: initiation, programming,measuring, storing, analyzing, communicating, predicting, anddisplaying. The adherent device may contain a subset of the followingphysiological sensors: bioimpedance, respiration, respiration ratevariability, heart rate (ave, min, max), heart rhythm, hear ratevariability (hereinafter “HRV”), heart rate turbulence (hereinafter“HRT”), heart sounds (e.g. S3), respiratory sounds, blood pressure,activity, posture, wake/sleep, orthopnea, temperature/heat flux, andweight. The activity sensor may comprise one or more of the following:ball switch, accelerometer, minute ventilation, HR, bioimpedance noise,skin temperature/heat flux, BP, muscle noise, posture.

The adherent device can wirelessly communicate with remote center 106.The communication may occur directly (via a cellular or Wi-Fi network),or indirectly through intermediate device 102. Intermediate device 102may consist of multiple devices, which can communicate wired orwirelessly to relay data to remote center 106.

In many embodiments, instructions are transmitted from remote site 106to a processor supported with the adherent patch on the patient, and theprocessor supported with the patient can receive updated instructionsfor the patient treatment and/or monitoring, for example while worn bythe patient.

FIG. 1B shows a bottom view of adherent device 100 as in FIG. 1Acomprising an adherent patch 110. Adherent patch 110 comprises a firstside, or a lower side 110A, that is oriented toward the skin of thepatient when placed on the patient. In many embodiments, adherent patch110 comprises a tape 110T which is a material, preferably breathable,with an adhesive 116A. Patient side 110A comprises adhesive 116A toadhere the patch 110 and adherent device 100 to patient P. Electrodes112A, 112B, 112C and 112D are affixed to adherent patch 110. In manyembodiments, at least four electrodes are attached to the patch, forexample six electrodes. In some embodiments the patch comprises twoelectrodes, for example two electrodes to measure the electrocardiogram(ECG) of the patient. Gel 114A, gel 114B, gel 114C and gel 114D can eachbe positioned over electrodes 112A, 112B, 112C and 112D, respectively,to provide electrical conductivity between the electrodes and the skinof the patient. In many embodiments, the electrodes can be affixed tothe patch 110, for example with known methods and structures such asrivets, adhesive, stitches, etc. In many embodiments, patch 110comprises a breathable material to permit air and/or vapor to flow toand from the surface of the skin.

FIG. 1C shows a top view of the adherent patch 100, as in FIG. 1B.Adherent patch 100 comprises a second side, or upper side 110B. In manyembodiments, electrodes 112A, 112B, 112C and 112D extend from lower side110A through adherent patch 110 to upper side 110B. An adhesive 116B canbe applied to upper side 110B to adhere structures, for example abreathable cover, to the patch such that the patch can support theelectronics and other structures when the patch is adhered to thepatient. The printed circuit board (hereinafter “PCB”) may comprisecompletely flex PCB, combined flex PCB and/or rigid PCB boards connectedby cable.

FIG. 1D shows a printed circuit boards and electronic components overadherent patch 110, as in FIGS. 1A to 1C. In some embodiments, a printedcircuit board (PCB), for example flex printed circuit board 120, may beconnected to electrodes 112A, 112B, 112C and 112D with connectors 122A,122B, 122C and 122D. Flex printed circuit board 120 can include traces123A, 123B, 123C and 123D that extend to connectors 122A, 122B, 122C and122D, respectively, on the flex printed circuit board. Connectors 122A,122B, 122C and 122D can be positioned on flex printed circuit board 120in alignment with electrodes 112A, 112B, 112C and 112D so as toelectrically couple the flex PCB with the electrodes. In someembodiments, connectors 122A, 122B, 122C and 122D may comprise insulatedwires and/or a film with conductive ink that provide strain reliefbetween the PCB and the electrodes. For example, connectors 122A, 122B,122C and 122D may comprise a flexible film, such as at least one ofknown polyester film or known polyurethane film, coated with aconductive ink, for example a conductive silver ink. In someembodiments, additional PCB's, for example rigid PCB's 120A, 120B, 120Cand 120D, can be connected to flex PCB 120. Electronic components 130can be connected to flex PCB 120 and/or mounted thereon. In someembodiments, electronic components 130 can be mounted on the additionalPCB's.

Electronic components 130 comprise components to take physiologicmeasurements, transmit data to remote center 106 and receive commandsfrom remote center 106. In many embodiments, electronics components 130may comprise known low power circuitry, for example complementary metaloxide semiconductor (CMOS) circuitry components. Electronics components130 comprise an activity sensor and activity circuitry 134, impedancecircuitry 136 and electrocardiogram circuitry, for example ECG circuitry138. In some embodiments, electronics circuitry 130 may comprise amicrophone and microphone circuitry 142 to detect an audio signal fromwithin the patient, and the audio signal may comprise a heart soundand/or a respiratory sound, for example an S3 heart sound and arespiratory sound with rales and/or crackles.

Electronics circuitry 130 may comprise a temperature sensor 177, forexample a thermistor in contact with the skin of the patient, andtemperature sensor circuitry 144 to measure a temperature of thepatient, for example a temperature of the skin of the patient. Atemperature sensor 177 may be used to determine the sleep and wake stateof the patient. The temperature of the patient can decrease as thepatient goes to sleep and increase when the patient wakes up.

Work in relation to embodiments of the present invention suggests thatskin temperature may effect impedance and/or hydration measurements, andthat skin temperature measurements may be used to correct impedanceand/or hydration measurements. In some embodiments, increase in skintemperature or heat flux can be associated with increased vasodilationnear the skin surface, such that measured impedance measurementdecreased, even through the hydration of the patient in deeper tissuesunder the skin remains substantially unchanged. Thus, use of thetemperature sensor can allow for correction of the hydration signals tomore accurately assess the hydration, for example extra cellularhydration, of deeper tissues of the patient, for example deeper tissuesin the thorax.

Electronics circuitry 130 may comprise a processor 146. Processor 146comprises a tangible medium, for example read only memory (ROM),electrically erasable programmable read only memory (EEPROM) and/orrandom access memory (RAM). Electronic circuitry 130 may comprise realtime clock and frequency generator circuitry 148. In some embodiments,processor 136 may comprise the frequency generator and real time clock.The processor can be configured to control a collection and transmissionof data from the impedance circuitry electrocardiogram circuitry and theaccelerometer. In many embodiments, device 100 comprise a distributedprocessor system, for example with multiple processors on device 100.

In many embodiments, electronics components 130 comprise wirelesscommunications circuitry 132 to communicate with remote center 106.Printed circuit board 120 may comprise an antenna to facilitate wirelesscommunication. The antennae may be integral with printed circuit board120 or may be separately coupled thereto. The wireless communicationcircuitry can be coupled to the impedance circuitry, theelectrocardiogram circuitry and the accelerometer to transmit to aremote center with a communication protocol at least one of thehydration signal, the electrocardiogram signal or the inclinationsignal. In specific embodiments, wireless communication circuitry isconfigured to transmit the hydration signal, the electrocardiogramsignal and the inclination signal to the remote center with a singlewireless hop, for example from wireless communication circuitry 132 tointermediate device 102. The communication protocol comprises at leastone of Bluetooth, Zigbee, WiFi, WiMax, IR, amplitude modulation orfrequency modulation. In many embodiments, the communications protocolcomprises a two way protocol such that the remote center is capable ofissuing commands to control data collection.

Intermediate device 102 may comprise a data collection system to collectand store data from the wireless transmitter. The data collection systemcan be configured to communicate periodically with the remote center.The data collection system can transmit data in response to commandsfrom remote center 106 and/or in response to commands from the adherentdevice.

Activity sensor and activity circuitry 134 can comprise many knownactivity sensors and circuitry. In many embodiments, the accelerometercomprises at least one of a piezoelectric accelerometer, capacitiveaccelerometer or electromechanical accelerometer. The accelerometer maycomprises a 3-axis accelerometer to measure at least one of aninclination, a position, an orientation or acceleration of the patientin three dimensions. Work in relation to embodiments of the presentinvention suggests that three dimensional orientation of the patient andassociated positions, for example sitting, standing, lying down, can bevery useful when combined with data from other sensors, for example ECGdata and/or hydration data.

Impedance circuitry 136 can generate both hydration data and respirationdata. In many embodiments, impedance circuitry 136 is electricallyconnected to electrodes 112A, 112B, 112C and 112D such that electrodes112A and 112D comprise outer electrodes that are driven with a current,or force electrodes. The current delivered between electrodes 112A and112D generates a measurable voltage between electrodes 112B and 112C,such that electrodes 112B and 112C comprise inner sense electrodes thatsense and/or measure the voltage in response to the current from theforce electrodes. In some embodiments, electrodes 112B and 112C maycomprise force electrodes and electrodes 112A and 112B may comprisesense electrodes. The voltage measured by the sense electrodes can beused measure the impedance of the patient to determine respiration rateand/or the hydration of the patient.

FIG. 1D1 shows an equivalent circuit 152 that can be used to determineoptimal frequencies for measuring patient hydration. Work in relation toembodiments of the present invention indicates that the frequency of thecurrent and/or voltage at the force electrodes can be selected so as toprovide impedance signals related to the extracellular and/orintracellular hydration of the patient tissue. Equivalent circuit 152comprises an intracellular resistance 156, or R(ICW) in series with acapacitor 154, and an extracellular resistance 158, or R(ECW).Extracellular resistance 158 is in parallel with intracellularresistance 156 and capacitor 154 related to capacitance of cellmembranes. In many embodiments, impedances can be measured and provideuseful information over a wide range of frequencies, for example fromabout 0.5 kHz to about 200 KHz. Work in relation to embodiments of thepresent invention suggests that extracellular resistance 158 can besignificantly related extracellular fluid and to cardiac decompensation,and that extracellular resistance 158 and extracellular fluid can beeffectively measured with frequencies in a range from about 0.5 kHz toabout 20 kHz, for example from about 1 kHz to about 10 kHz. In someembodiments, a single frequency can be used to determine theextracellular resistance and/or fluid. As sample frequencies increasefrom about 10 kHz to about 20 kHz, capacitance related to cell membranesdecrease the impedance, such that the intracellular fluid contributes tothe impedance and/or hydration measurements. Thus, many embodiments ofthe present invention employ measure hydration with frequencies fromabout 0.5 kHz to about 20 kHz to determine patient hydration.

In many embodiments, impedance circuitry 136 can be configured todetermine respiration of the patient. In specific embodiments, theimpedance circuitry can measure the hydration at 25 Hz intervals, forexample at 25 Hz intervals using impedance measurements with a frequencyfrom about 0.5 kHz to about 20 kHz.

ECG circuitry 138 can generate electrocardiogram signals and data fromtwo or more of electrodes 112A, 112B, 112C and 112D in many ways. Insome embodiments, ECG circuitry 138 is connected to inner electrodes112B and 122C, which may comprise sense electrodes of the impedancecircuitry as described above. In some embodiments, ECG circuitry 138 canbe connected to electrodes 112A and 112D so as to increase spacing ofthe electrodes. The inner electrodes may be positioned near the outerelectrodes to increase the voltage of the ECG signal measured by ECGcircuitry 138. In many embodiments, the ECG circuitry may measure theECG signal from electrodes 112A and 112D when current is not passedthrough electrodes 112A and 112D, for example with switches as describedin U.S. App. No. 60/972,527, the full disclosure of which has beenpreviously incorporated herein by reference.

FIG. 1E shows batteries 150 positioned over the flex printed circuitboard and electronic components as in FIG. 1D. Batteries 150 maycomprise rechargeable batteries that can be removed and/or recharged. Insome embodiments, batteries 150 can be removed from the adherent patchand recharged and/or replaced.

FIG. 1F shows a top view of a cover 162 over the batteries, electroniccomponents and flex printed circuit board as in FIGS. 1A to 1E. In manyembodiments, an electronics housing 160 may be disposed under cover 162to protect the electronic components, and in some embodimentselectronics housing 160 may comprise an encapsulant over the electroniccomponents and PCB. In some embodiments, cover 162 can be adhered toadherent patch 110 with an adhesive 164 on an underside of cover 162. Inmany embodiments, electronics housing 160 may comprise a water proofmaterial, for example a sealant adhesive such as epoxy or siliconecoated over the electronics components and/or PCB. In some embodiments,electronics housing 160 may comprise metal and/or plastic. Metal orplastic may be potted with a material such as epoxy or silicone.

Cover 162 may comprise many known biocompatible cover, casing and/orhousing materials, such as elastomers, for example silicone. Theelastomer may be fenestrated to improve breathability. In someembodiments, cover 162 may comprise many known breathable materials, forexample polyester, polyamide, nylon and/or elastane (Spandex™). Thebreathable fabric may be coated to make it water resistant, waterproof,and/or to aid in wicking moisture away from the patch.

FIG. 1G shows a side view of adherent device 100 as in FIGS. 1A to 1F.Adherent device 100 comprises a maximum dimension, for example a length170 from about 4 to 10 inches (from about 100 mm to about 250 mm), forexample from about 6 to 8 inches (from about 150 mm to about 200 mm). Insome embodiments, length 170 may be no more than about 6 inches (no morethan about 150 mm). Adherent device 100 comprises a thickness 172.Thickness 172 may comprise a maximum thickness along a profile of thedevice. Thickness 172 can be from about 0.2 inches to about 0.6 inches(from about 5 mm to about 15 mm), from about 0.2 inches to about 0.4inches (from about 5 mm to about 10 mm), for example about 0.3 inches(about 7.5 mm).

FIG. 1H shown a bottom isometric view of adherent device 100 as in FIGS.1A to 1G. Adherent device 100 comprises a width 174, for example amaximum width along a width profile of adherent device 100. Width 174can be from about 2 to about 4 inches (from about 50 mm to 100 mm), forexample about 3 inches (about 75 mm).

FIGS. 1I and 1J show a side cross-sectional view and an exploded view,respectively, of adherent device 100 as in FIGS. 1A to 1H. In manyembodiments, device 100 comprises several layers.

FIGS. 1I1 and 1J1 show a side cross-sectional view and an exploded view,respectively, of embodiments of the adherent device with a temperaturesensor affixed to the gel cover. In these embodiments, gel cover 180extends over a wider area than in the embodiments shown in FIGS. 1I and1J. Temperature sensor 177 is disposed over a peripheral portion of gelcover 180. Temperature sensor 177 can be affixed to gel cover 180 suchthat the temperature sensor can move when the gel cover stretches andtape stretch with the skin of the patient. Temperature sensor 177 may becoupled to temperature sensor circuitry 144 through a flex connectioncomprising at least one of wires, shielded wires, non-shielded wires, aflex circuit, or a flex PCB. This coupling of the temperature sensorallows the temperature near the skin to be measured though thebreathable tape and the gel cover. The temperature sensor can be affixedto the breathable tape, for example through a cutout in the gel coverwith the temperature sensor positioned away from the gel pads. A heatflux sensor can be positioned near the temperature sensor, for exampleto measure heat flux through to the gel cover, and the heat flux sensorcoupled to heat flux circuitry similar to the temperature sensor.

The adherent device comprises electrodes 112A1, 112B1, 112C1 and 112D1configured to couple to tissue through apertures in the breathable tape110T. Electrodes 112A1, 112B1, 112C1 and 112D1 can be fabricated in manyways. For example, electrodes 112A1, 112B1, 112C1 and 112D1 can beprinted on a flexible connector 112F, such as silver ink onpolyurethane. Breathable tape 110T comprise apertures 180A1, 180B1,180C1 and 180D1. Electrodes 112A1, 112B1, 112C1 and 112D1 are exposed tothe gel through apertures 180A1, 180B1, 180C1 and 180D1 of breathabletape 110T. Gel 114A, gel 114B, gel 114C and gel 114D can be positionedover electrodes 112A1, 112B1, 112C1 and 112D1 and the respectiveportions of breathable tape 110T proximate apertures 180A1, 180B1, 180C1and 180D1, so as to couple electrodes 112A1, 112B1, 112C1 and 112D1 tothe skin of the patient. The flexible connector 112F comprising theelectrodes can extend from under the gel cover to the printed circuitboard to connect to the printed circuit boards and/or componentssupported thereon. For example, flexible connector 112F may compriseflexible connector 122A to provide strain relief, as described above.

In many embodiments, gel 114A, or gel layer, comprises a hydrogel thatis positioned on electrode 112A to provide electrical conductivitybetween the electrode and the skin. In many embodiments, gel 114Acomprises a hydrogel that provides a conductive interface between skinand electrode, so as to reduce impedance between electrode/skininterface. In many embodiments, gel may comprise water, glycerol, andelectrolytes, pharmacological agents, such as beta blockers, aceinhibiters, diuretics, steroid for inflammation, antibiotic, antifungalagent. In specific embodiments the gel may comprise cortisone steroid.The gel layer may comprise many shapes, for example, square, circular,oblong, star shaped, many any polygon shapes. In specific embodiments,the gel layer may comprise at least one of a square or circular geometrywith a dimension in a range from about 0.005″ to about 0.100″, forexample within a range from about 0.015″-0.070″, in some embodimentswithin a range from about 0.015″-0.040″, and in specific embodimentswithin a range from about 0.020″-0.040″. In many embodiments, the gellayer of each electrode comprises an exposed surface area to contact theskin within a range from about 100 mm^2 to about 1500 mm^2, for examplea range from about 250 mm^2 to about 750 mm^2, and in specificembodiments within a range from about 350 mm^2 to about 650 mm^2 Work inrelation with embodiments of the present invention suggests that suchdimensions and/or exposed surface areas can provide enough gel area forrobust skin interface without excessive skin coverage. In manyembodiments, the gel may comprise an adhesion to skin, as may be testedwith a 1800 degree peel test on stainless steel, of at least about 3oz/in, for example an adhesion within a range from about 5-10 oz/in. Inmany embodiments, a spacing between gels is at least about 5 mm, forexample at least about 10 mm. Work in relation to embodiments of thepresent invention suggests that this spacing may inhibit the gels fromrunning together so as to avoid crosstalk between the electrodes. Inmany embodiments, the gels comprise a water content within a range fromabout 20% to about 30%, a volume resistivity within a range from about500 to 2000 ohm-cm, and a pH within a range from about 3 to about 5.

In many embodiments, the electrodes, for example electrodes 112A to112D, may comprise an electrode layer. A 0.001″-0.005″ polyester stripwith silver ink for traces can extend to silver/silver chlorideelectrode pads. In many embodiments, the electrodes can provideelectrical conduction through hydrogel to skin, and in some embodimentsmay be coupled directly to the skin. Although at least 4 electrodes areshown, some embodiments comprise at least two electrodes, for example 2electrodes. In some embodiments, the electrodes may comprise at leastone of carbon-filled ABS plastic, silver, nickel, or electricallyconductive acrylic tape. In specific embodiments, the electrodes maycomprise at least one of carbon-filled ABS plastic, Ag/AgCl. Theelectrodes may comprise many geometric shapes to contact the skin, forexample at least one of square, circular, oblong, star shaped, polygonshaped, or round. In specific embodiments, a dimension across a width ofeach electrodes is within a range from about 002″ to about 0.050″, forexample from about 0.010 to about 0.040″. In many a surface area of theelectrode toward the skin of the patient is within a range from about 25mm^2 to about 1500 mm^2, for example from about 75 mm^2 to about 150mm^2 In many embodiments, the electrode comprises a tape that may coverthe gel near the skin of the patient. In specific embodiments, the twoinside electrodes may comprise force, or current electrodes, with acenter to center spacing within a range from about 20 to about 50 mm. Inspecific embodiments, the two outside electrodes may comprisemeasurement electrodes, for example voltage electrodes, and acenter-center spacing between adjacent voltage and current electrodes iswithin a range from about 15 mm to about 35 mm. Therefore, in manyembodiments, a spacing between inner electrodes may be greater than aspacing between an inner electrode and an outer electrode.

In many embodiments, adherent patch 110 may comprise a layer ofbreathable tape 110T, for example a known breathable tape, such astricot-knit polyester fabric. In many embodiments, breathable tape 110Tcomprises a backing material, or backing 111, with an adhesive. In manyembodiments, the patch adheres to the skin of the patient's body, andcomprises a breathable material to allow moisture vapor and air tocirculate to and from the skin of the patient through the tape. In manyembodiments, the backing is conformable and/or flexible, such that thedevice and/or patch does not become detached with body movement. In manyembodiments, backing can sufficiently regulate gel moisture in absenceof gel cover. In many embodiments, adhesive patch may comprise from 1 to2 pieces, for example 1 piece. In many embodiments, adherent patch 110comprises pharmacological agents, such as at least one of beta blockers,ace inhibiters, diuretics, steroid for inflammation, antibiotic, orantifungal agent. In specific embodiments, patch 110 comprises cortisonesteroid. Patch 110 may comprise many geometric shapes, for example atleast one of oblong, oval, butterfly, dogbone, dumbbell, round, squarewith rounded corners, rectangular with rounded corners, or a polygonwith rounded corners. In specific embodiments, a geometric shape ofpatch 110 comprises at least one of an oblong, an oval or round. In manyembodiments, the geometric shape of the patch comprises a radius on eachcorner that is no less than about one half a width and/or diameter oftape. Work in relation to embodiments of the present invention suggeststhat rounding the corner can improve adherence of the patch to the skinfor an extended period of time because sharp corners, for example rightangle corners, can be easy to peel. In specific embodiments, a thicknessof adherent patch 110 is within a range from about 0.001″ to about0.020″, for example within a range from about 0.005″ to about 0.010″.Work in relation to embodiments of the present invention indicates thatthese ranges of patch thickness can improve adhesion of the device tothe skin of the patient for extended periods as a thicker adhesivepatch, for example tape, may peel more readily. In many embodiments,length 170 of the patch is within a range from about 2″ to about 10″,width 174 of the patch is within a range from about 1″ to about 5″. Inspecific embodiments, length 170 is within a range from about 4″ toabout 8″ and width 174 is within a range from about 2″ to about 4″. Inmany embodiments, an adhesion to the skin, as measured with a 180 degreepeel test on stainless steel, can be within a range from about 10 toabout 100 oz/in width, for example within a range from about 30 to about70 oz/in width. Work in relation to embodiments of the present inventionsuggests that adhesion within these ranges may improve the measurementcapabilities of the patch because if the adhesion is too low, patch willnot adhere to the skin of the patient for a sufficient period of timeand if the adhesion is too high, the patch may cause skin irritationupon removal. In many embodiments adherent patch 110 comprises amoisture vapor transmission rate (MVTR, g/m^2/24 hrs) per AmericanStandard for Testing and Materials E-96 (ASTM E-96) is at least about400, for example at least about 1000. Work in relation to embodiments ofthe present invention suggest that MVTR values as specified above canprovide improved comfort, for example such that in many embodiments skindoes not itch. In some embodiments, the breathable tape 110T of adherentpatch 110 may comprise a porosity (sec./100 cc/in²) within a wide rangeof values, for example within a range from about 0 to about 200. Theporosity of breathable tape 110T may be within a range from about 0 toabout 5. The above amounts of porosity can minimize itching of thepatient's skin when the patch is positioned on the skin of the patient.In many embodiments, the MVTR values above may correspond to a MVTRthrough both the gel cover and the breathable tape. The above MVTRvalues may also correspond to an MVTR through the breathable tape, thegel cover and the breathable cover. The MVTR can be selected to minimizepatient discomfort, for example itching of the patient's skin.

In some embodiments, the breathable tape may contain and elute apharmaceutical agent, such as an antibiotic, anti-inflammatory orantifungal agent, when the adherent device is placed on the patient.

In many embodiments, tape 110T of adherent patch 110 may comprisebacking material, or backing 111, such as a fabric configured to provideproperties of patch 110 as described above. In many embodiments backing111 provides structure to breathable tape 110T, and many functionalproperties of breathable tape 110T as described above. In manyembodiments, backing 111 comprises at least one of polyester,polyurethane, rayon, nylone, breathable plastic film; woven, nonwoven,spunlace, knit, film, or foam. In specific embodiments, backing 111 maycomprise polyester tricot knit fabric. In many embodiments, backing 111comprises a thickness within a range from about 0.0005″ to about 0.020″,for example within a range from about 0.005″ to about 0.010″.

In many embodiments, an adhesive 116A, for example breathable tapeadhesive comprising a layer of acrylate pressure sensitive adhesive, canbe disposed on underside 110A of patch 110. In many embodiments,adhesive 116A adheres adherent patch 110 comprising backing 111 to theskin of the patient, so as not to interfere with the functionality ofbreathable tape, for example water vapor transmission as describedabove. In many embodiments, adhesive 116A comprises at least one ofacrylate, silicone, synthetic rubber, synthetic resin, hydrocolloidadhesive, pressure sensitive adhesive (PSA), or acrylate pressuresensitive adhesive. In many embodiments, adhesive 116A comprises athickness from about 0.0005″ to about 0.005″, in specific embodiments nomore than about 0.003″. Work in relation to embodiments of the presentinvention suggests that these thicknesses can allow the tape to breatheand/or transmit moisture, so as to provide patient comfort.

A gel cover 180, or gel cover layer, for example a polyurethanenon-woven tape, can be positioned over patch 110 comprising thebreathable tape. A PCB layer, for example flex printed circuit board120, or flex PCB layer, can be positioned over gel cover 180 withelectronic components 130 connected and/or mounted to flex printedcircuit board 120, for example mounted on flex PCB so as to comprise anelectronics layer disposed on the flex PCB layer. In many embodiments,the adherent device may comprise a segmented inner component, forexample the PCB may be segmented to provide at least some flexibility.In many embodiments, the electronics layer may be encapsulated inelectronics housing 160 which may comprise a waterproof material, forexample silicone or epoxy. In many embodiments, the electrodes areconnected to the PCB with a flex connection, for example trace 123A offlex printed circuit board 120, so as to provide strain relive betweenthe electrodes 112A, 112B, 112C and 112D and the PCB.

Gel cover 180 can inhibit flow of gel 114A and liquid. In manyembodiments, gel cover 180 can inhibit gel 114A from seeping throughbreathable tape 110T to maintain gel integrity over time. Gel cover 180can also keep external moisture from penetrating into gel 114A. Forexample gel cover 180 can keep liquid water from penetrating though thegel cover into gel 114A, while allowing moisture vapor from the gel, forexample moisture vapor from the skin, to transmit through the gel cover.The gel cover may comprise a porosity at least 200 sec./100 cc/in², andthis porosity can ensure that there is a certain amount of protectionfrom external moisture for the hydrogel.

In many embodiments, the gel cover can regulate moisture of the gel nearthe electrodes so as to keeps excessive moisture, for example from apatient shower, from penetrating gels near the electrodes. In manyembodiments, the gel cover may avoid release of excessive moisture formthe gel, for example toward the electronics and/or PCB modules. Gelcover 180 may comprise at least one of a polyurethane, polyethylene,polyolefin, rayon, PVC, silicone, non-woven material, foam, or a film.In many embodiments gel cover 180 may comprise an adhesive, for examplea acrylate pressure sensitive adhesive, to adhere the gel cover toadherent patch 110. In specific embodiments gel cover 180 may comprise apolyurethane film with acrylate pressure sensitive adhesive. In manyembodiments, a geometric shape of gel cover 180 comprises at least oneof oblong, oval, butterfly, dogbone, dumbbell, round, square,rectangular with rounded corners, or polygonal with rounded corners. Inspecific embodiments, a geometric shape of gel cover 180 comprises atleast one of oblong, oval, or round. In many embodiments, a thickness ofgel cover is within a range from about 0.0005″ to about 0.020″, forexample within a range from about 0.0005 to about 0.010″. In manyembodiments, gel cover 180 can extend outward from about 0-20 mm from anedge of gels, for example from about 5-15 mm outward from an edge of thegels.

In many embodiments, the breathable tape of adherent patch 110 comprisesa first mesh with a first porosity and gel cover 180 comprises abreathable tape with a second porosity, in which the second porosity isless than the first porosity to inhibit flow of the gel through thebreathable tape.

In many embodiments, device 100 includes a printed circuitry, forexample a printed circuitry board (PCB) module that includes at leastone PCB with electronics component mounted thereon on and the battery,as described above. In many embodiments, the PCB module comprises tworigid PCB modules with associated components mounted therein, and thetwo rigid PCB modules are connected by flex circuit, for example a flexPCB. In specific embodiments, the PCB module comprises a known rigid FR4type PCB and a flex PCB comprising known polyimide type PCB. In specificembodiments, the PCB module comprises a rigid PCB with flexinterconnects to allow the device to flex with patient movement. Thegeometry of flex PCB module may comprise many shapes, for example atleast one of oblong, oval, butterfly, dogbone, dumbbell, round, square,rectangular with rounded corners, or polygon with rounded corners. Inspecific embodiments the geometric shape of the flex PCB modulecomprises at least one of dogbone or dumbbell. The PCB module maycomprise a PCB layer with flex PCB 120 can be positioned over gel cover180 and electronic components 130 connected and/or mounted to flex PCB120 so as to comprise an electronics layer disposed on the flex PCB. Inmany embodiments, the adherent device may comprise a segmented innercomponent, for example the PCB, for limited flexibility. The printedcircuit may comprise polyester film with silver traces printed thereon.

In many embodiments, the electronics layer may be encapsulated inelectronics housing 160. Electronics housing 160 may comprise anencapsulant, such as a dip coating, which may comprise a waterproofmaterial, for example silicone and/or epoxy. In many embodiments, thePCB encapsulant protects the PCB and/or electronic components frommoisture and/or mechanical forces. The encapsulant may comprisesilicone, epoxy, other adhesives and/or sealants. In some embodiments,the electronics housing may comprising metal and/or plastic housing andpotted with aforementioned sealants and/or adhesives.

In many embodiments, the electrodes are connected to the PCB with a flexconnection, for example trace 123A of flex PCB 120, so as to providestrain relive between the electrodes 112A, 112B, 112C and 112D and thePCB. In such embodiments, motion of the electrodes relative to theelectronics modules, for example rigid PCB's 120A, 120B, 120C and 120Dwith the electronic components mounted thereon, does not compromiseintegrity of the electrode/hydrogel/skin contact. In some embodiments,the electrodes can be connected to the PCB and/or electronics modulewith a flex PCB 120, such that the electrodes and adherent patch canmove independently from the PCB module. In many embodiments, the flexconnection comprises at least one of wires, shielded wires, non-shieldedwires, a flex circuit, or a flex PCB. In specific embodiments, the flexconnection may comprise insulated, non-shielded wires with loops toallow independent motion of the PCB module relative to the electrodes.

In many embodiments, cover 162 can encase the flex PCB and/orelectronics and can be adhered to at least one of the electronics, theflex PCB or adherent patch 110, so as to protect at least theelectronics components and the PCB. Cover 162 can attach to adherentpatch 110 with adhesive 116B. Cover 162 can comprise many knownbiocompatible cover materials, for example silicone. Cover 162 cancomprise an outer polymer cover to provide smooth contour withoutlimiting flexibility. In many embodiments, cover 162 may comprise abreathable fabric. Cover 162 may comprise many known breathable fabrics,for example breathable fabrics as described above. In some embodiments,the breathable cover may comprise a breathable water resistant cover. Insome embodiments, the breathable fabric may comprise polyester, nylon,polyamide, and/or elastane (Spandex™) to allow the breathable fabric tostretch with body movement. In some embodiments, the breathable tape maycontain and elute a pharmaceutical agent, such as an antibiotic,anti-inflammatory or antifungal agent, when the adherent device isplaced on the patient.

In specific embodiments, cover 162 comprises at least one of polyester,5-25% elastane/spandex, polyamide fabric; silicone, a polyester knit, apolyester knit without elastane, or a thermoplastic elastomer. In manyembodiments cover 162 comprises at least 400% elongation. In specificembodiments, cover 162 comprises at least one of a polyester knit with10-20% spandex or a woven polyamide with 10-20% spandex. In manyembodiments, cover 162 comprises a water repellent coating and/or layeron outside, for example a hydrophobic coating, and a hydrophilic coatingon inside to wick moisture from body. In many embodiments the waterrepellent coating on the outside comprises a stain resistant coating.Work in relation to embodiments of the present invention suggests thatthese coatings can be important to keep excessive moisture from the gelsnear the electrodes and to remove moisture from body so as to providepatient comfort.

The breathable cover 162 and adherent patch 110 comprise breathable tapecan be configured to couple continuously for at least one week the atleast one electrode to the skin so as to measure breathing of thepatient. The breathable tape may comprise the stretchable breathablematerial with the adhesive and the breathable cover may comprises astretchable breathable material connected to the breathable tape, asdescribed above, such that both the adherent patch and cover can stretchwith the skin of the patient. The breathable cover may also comprise awater resistant material. Arrows 182 show stretching of adherent patch110, and the stretching of adherent patch can be at least twodimensional along the surface of the skin of the patient. As notedabove, connectors 122A, 122B, 122C and 122D between PCB 130 andelectrodes 112A, 112B, 112C and 112D may comprise insulated wires thatprovide strain relief between the PCB and the electrodes, such that theelectrodes can move with the adherent patch as the adherent patchcomprising breathable tape stretches. Arrows 184 show stretching ofcover 162, and the stretching of the cover can be at least twodimensional along the surface of the skin of the patient.

Cover 162 can be attached to adherent patch 110 with adhesive 116B suchthat cover 162 stretches and/or retracts when adherent patch 110stretches and/or retracts with the skin of the patient. For example,cover 162 and adherent patch 110 can stretch in two dimensions alonglength 170 and width 174 with the skin of the patient, and stretchingalong length 170 can increase spacing between electrodes. Stretching ofthe cover and adherent patch 110, for example in two dimensions, canextend the time the patch is adhered to the skin as the patch can movewith the skin such that the patch remains adhered to the skin.Electronics housing 160 can be smooth and allow breathable cover 162 toslide over electronics housing 160, such that motion and/or stretchingof cover 162 is slidably coupled with housing 160. The printed circuitboard can be slidably coupled with adherent patch 110 that comprisesbreathable tape 110T, such that the breathable tape can stretch with theskin of the patient when the breathable tape is adhered to the skin ofthe patient, for example along two dimensions comprising length 170 andwidth 174.

The stretching of the adherent device 100 along length 170 and width 174can be characterized with a composite modulus of elasticity determinedby stretching of cover 162, adherent patch 110 comprising breathabletape 110T and gel cover 180. For the composite modulus of the compositefabric cover-breathable tape-gel cover structure that surrounds theelectronics, the composite modulus may comprise no more than about 1MPa, for example no more than about 0.3 MPa at strain of no more thanabout 5%. These values apply to any transverse direction against theskin.

The stretching of the adherent device 100 along length 170 and width174, may also be described with a composite stretching elongation ofcover 162, adherent patch 110 comprising breathable tape breathable tape110T and gel cover 180. The composite stretching elongation may comprisea percentage of at least about 10% when 3 kg load is a applied, forexample at least about 100% when the 3 kg load applied. Thesepercentages apply to any transverse direction against the skin.

The printed circuit board may be adhered to the adherent patch 110comprising breathable tape 110T at a central portion, for example asingle central location, such that adherent patch 110 can stretch aroundthis central region. The central portion can be sized such that theadherence of the printed circuit board to the breathable tape does nothave a substantial effect of the modulus of the composite modulus forthe fabric cover, breathable tape and gel cover, as described above. Forexample, the central portion adhered to the patch may be less than about100 mm², for example with dimensions of approximately 10 mm by 10 mm(about 0.5″ by 0.5″). Such a central region may comprise no more thanabout 10% of the area of patch 110, such that patch 110 can stretch withthe skin of the patient along length 170 and width 174 when the patch isadhered to the patient.

The cover material may comprise a material with a low recovery, whichcan minimize retraction of the breathable tape from the pulling by thecover. Suitable cover materials with a low recovery include at least oneof polyester or nylon, for example polyester or nylon with a loose knit.The recovery of the cover material may be within a range from about 0%recovery to about 25% recovery. Recovery can refer to the percentage ofretraction the cover material that occurs after the material has beenstretched from a first length to a second length. For example, with 25%recovery, a cover that is stretched from a 4 inch length to a 5 inchlength will retract by 25% to a final length of 4.75 inches.

Electronics components 130 can be affixed to printed circuit board 120,for example with solder, and the electronics housing can be affixed overthe PCB and electronics components, for example with dip coating, suchthat electronics components 130, printed circuit board 120 andelectronics housing 160 are coupled together. Electronics components130, printed circuit board 120, and electronics housing 160 are disposedbetween the stretchable breathable material of adherent patch 110 andthe stretchable breathable material of cover 160 so as to allow theadherent patch 110 and cover 160 to stretch together while electronicscomponents 130, printed circuit board 120, and electronics housing 160do not stretch substantially, if at all. This decoupling of electronicshousing 160, printed circuit board 120 and electronic components 130 canallow the adherent patch 110 comprising breathable tape to move with theskin of the patient, such that the adherent patch can remain adhered tothe skin for an extended time of at least one week, for example two ormore weeks.

An air gap 169 may extend from adherent patch 110 to the electronicsmodule and/or PCB, so as to provide patient comfort. Air gap 169 allowsadherent patch 110 and breathable tape 110T to remain supple and move,for example bend, with the skin of the patient with minimal flexingand/or bending of printed circuit board 120 and electronic components130, as indicated by arrows 186. Printed circuit board 120 andelectronics components 130 that are separated from the breathable tape110T with air gap 169 can allow the skin to release moisture as watervapor through the breathable tape, gel cover, and breathable cover. Thisrelease of moisture from the skin through the air gap can minimize, andeven avoid, excess moisture, for example when the patient sweats and/orshowers.

The breathable tape of adherent patch 110 may comprise a first mesh witha first porosity and gel cover 180 may comprise a breathable tape with asecond porosity, in which the second porosity is less than the firstporosity to minimize, and even inhibit, flow of the gel through thebreathable tape. The gel cover may comprise a polyurethane film with thesecond porosity.

Cover 162 may comprise many shapes. In many embodiments, a geometry ofcover 162 comprises at least one of oblong, oval, butterfly, dogbone,dumbbell, round, square, rectangular with rounded corners, or polygonalwith rounded corners. In specific embodiments, the geometric of cover162 comprises at least one of an oblong, an oval or a round shape.

Cover 162 may comprise many thicknesses and/or weights. In manyembodiments, cover 162 comprises a fabric weight: within a range fromabout 100 to about 200 g/m^2, for example a fabric weight within a rangefrom about 130 to about 170 g/m^2.

In many embodiments, cover 162 can attach the PCB module to adherentpatch 110 with cover 162, so as to avoid interaction of adherent patch110C 110 with the PCB having the electronics mounted therein. Cover 162can be attached to breathable tape 110T and/or electronics housing 160comprising over the encapsulated PCB. In many embodiments, adhesive 116Battaches cover 162 to adherent patch 110. In many embodiments, cover 162attaches to adherent patch 110 with adhesive 116B, and cover 162 isadhered to the PCB module with an adhesive 161 on the upper surface ofthe electronics housing. Thus, the PCB module can be suspended above theadherent patch via connection to cover 162, for example with a gap 169between the PCB module and adherent patch. In many embodiments, gap 169permits air and/or water vapor to flow between the adherent patch andcover, for example through adherent patch 110 and cover 162, so as toprovide patient comfort.

In many embodiments, adhesive 116B is configured such that adherentpatch 110 and cover 162 can be breathable from the skin to above cover162 and so as to allow moisture vapor and air to travel from the skin tooutside cover 162. In many embodiments, adhesive 116B is applied in apattern on adherent patch 110 such that the patch and cover can beflexible so as to avoid detachment with body movement. Adhesive 116B canbe applied to upper side 110B of patch 110 and comprise many shapes, forexample a continuous ring, dots, dashes around the perimeter of adherentpatch 110 and cover 162. Adhesive 116B may comprise at least one ofacrylate, silicone, synthetic rubber, synthetic resin, pressuresensitive adhesive (PSA), or acrylate pressure sensitive adhesive.Adhesive 16B may comprise a thickness within a range from about 0.0005″to about 0.005″, for example within a range from about 0.001-0.005″. Inmany embodiments, adhesive 116B comprises a width near the edge of patch110 and/or cover 162 within a range from about 2 to about 15 mm, forexample from about 3 to about 7 near the periphery. In many embodimentswith such widths and/or thickness near the edge of the patch and/orcover, the tissue adhesion may be at least about 30 oz/in, for exampleat least about 40 oz/in, such that the cover remains attached to theadhesive patch when the patient moves.

In many embodiments, the cover is adhered to adherent patch 110comprising breathable tape 110T at least about 1 mm away from an outeredge of adherent patch 110. This positioning protects the adherent patchcomprising breathable tape 110T from peeling away from the skin andminimizes edge peeling, for example because the edge of the patch can bethinner. In some embodiments, the edge of the cover may be adhered atthe edge of the adherent patch, such that the cover can be slightlythicker at the edge of the patch which may, in some instances,facilitate peeling of the breathable tape from the skin of the patient.

Gap 169 extend from adherent patch 110 to the electronics module and/orPCB a distance within a range from about 0.25 mm to about 4 mm, forexample within a range from about 0.5 mm to about 2 mm.

In many embodiments, the adherent device comprises a patch component andat least one electronics module. The patch component may compriseadherent patch 110 comprising the breathable tape with adhesive coating116A, at least one electrode, for example electrode 114A and gel 114.The at least one electronics module can be separable from the patchcomponent. In many embodiments, the at least one electronics modulecomprises the flex printed circuit board 120, electronic components 130,electronics housing 160 and cover 162, such that the flex printedcircuit board, electronic components, electronics housing and cover arereusable and/or removable for recharging and data transfer, for exampleas described above. In many embodiments, adhesive 116B is coated onupper side 110A of adherent patch 110B, such that the electronics modulecan be adhered to and/or separated from the adhesive component. Inspecific embodiments, the electronic module can be adhered to the patchcomponent with a releasable connection, for example with Velcro™, aknown hook and loop connection, and/or snap directly to the electrodes.Two electronics modules can be provided, such that one electronicsmodule can be worn by the patient while the other is charged, asdescribed above. Monitoring with multiple adherent patches for anextended period is described in U.S. Pat. App. No. 60/972,537, the fulldisclosure of which has been previously incorporated herein byreference. Many patch components can be provided for monitoring over theextended period. For example, about 12 patches can be used to monitorthe patient for at least 90 days with at least one electronics module,for example with two reusable electronics modules.

At least one electrode 112A can extend through at least one aperture180A in the breathable tape 110.

In some embodiments, the adhesive patch may comprise a medicated patchthat releases a medicament, such as antibiotic, beta-blocker, ACEinhibitor, diuretic, or steroid to reduce skin irritation. The adhesivepatch may comprise a thin, flexible, breathable patch with a polymergrid for stiffening. This grid may be anisotropic, may use electroniccomponents to act as a stiffener, may use electronics-enhanced adhesiveelution, and may use an alternating elution of adhesive and steroid.

FIG. 1K shows at least one electrode 190 configured to electricallycouple to a skin of the patient through a breathable tape 192. In manyembodiments, at least one electrode 190 and breathable tape 192 compriseelectrodes and materials similar to those described above. Electrode 190and breathable tape 192 can be incorporated into adherent devices asdescribed above, so as to provide electrical coupling between the skinand an electrode through the breathable tape, for example with the gel.

FIGS. 2A and 2B show components of an adherent device 200 comprising anadhesive patch 210 and connection structures to provide strain relief soas to decouple the patch from an electronics module 220. Adherent device200 comprises many structures similar to those shown above. Adherentdevice 200 comprises electrodes 212A, 212B, 212C and 212D affixed toadherent patch 210. Adherent device 200 may comprise a gel, for examplegel 214A over the electrodes, for example over electrode 212A.Electrodes 212A, 212B, 212C and 212D are connected to electronics module220 with structures 223A, 223B, 223C and 223D. Electronics module 220may comprise PCB with components mounted thereon, as described above. Inmany embodiments, structures 223A, 223B, 223C and 223D connect adhesivepatch 210 to electronics module 220 with a flexible connection. In manyembodiments, structures 223A, 223B, 223C and 223D comprise curvedflexible wires, for example spirals and/or loops of wire that connectelectrodes 212A, 212B, 212C and 212D to an electronics module 220.Structures 223A, 223B, 223C and 223D may comprise polyester film withsilver traces coupled to silver/silver chloride electrodes to providestrain relief. Adhesive patch 210 comprises a lower side 210A toward theskin of the patient and an upper side 210B away from the skin of thepatient. Adhesive 216B is disposed on upper side 210B of patch 210 toconnect the adhesive patch to a cover, as described above. Electronicsmodule 220 can be connected to the cover, as described above, such thatmodule 220 is suspended above adhesive patch 210 with a gap 269. Gap 269can decouple movement between patch 210 and electronic module 220. Inmany embodiments, gap 260 allows adhesive patch 210 and/or device 200 tobreath, for example from the skin through the patch and cover to theoutside of the cover, as described above. A gel cover 280, or gel coverlayer, for example a polyurethane non-woven tape, can be positioned overpatch 210 comprising the breathable tape.

In many embodiments, gap 269 can extend from adherent patch 210 to theelectronics module 220 and/or PCB a distance within a range from about0.25 mm to about 4 mm, for example within a range from about 0.5 mm toabout 2 mm.

While the exemplary embodiments have been described in some detail, byway of example and for clarity of understanding, those of skill in theart will recognize that a variety of modifications, adaptations, andchanges may be employed. Hence, the scope of the present inventionshould be limited solely by the appended claims.

What claimed is:
 1. An adherent device to monitor a patient for anextended period, the device comprising: a first adherent patchcomprising a breathable tape with an adhesive coating to adhere thebreathable tape to a skin of the patient, the adherent patch alsocomprising a plurality of electrodes affixed to the breathable tape andcapable of electrically coupling to the skin of the patient; and anelectronics module comprising electrocardiogram circuitry coupled to atleast two of the plurality of electrodes and impedance circuitry coupledto at least two of the plurality of electrodes, the electronics modulealso comprising wireless communications circuitry coupled to theelectrocardiogram circuitry and to the impedance circuitry to transmitto a remote server another device an electrocardiogram signal derivedfrom an output of the electrocardiogram circuitry and a hydration signalderived from an output of the impedance circuitry; wherein theelectronics module is coupled to the breathable tape to support theelectronics module when the tape is adhered to the patient; and whereinthe electronics module is separable from the adherent patch such thatthe electronics module can be reused with a second adherent patch toprovide monitoring for an extended period; wherein the adherent patchfurther comprises a respective gel disposed over a contact surface ofeach of the plurality of electrodes to electrically connect therespective electrode to the skin of the patient; and wherein theadherent patch further comprises a gel cover positioned over thebreathable tape to inhibit a flow of the gel through the breathabletape, and wherein the electronics module is located over the gel coversuch that the gel cover is disposed between the breathable tape and theelectronics module, wherein the gel cover is configured to inhibittransmission of liquid water and permit transmission of moisture vapor.2. The adherent device of claim 1, wherein the electronics modulefurther comprises an accelerometer, and wherein the wirelesscommunications circuitry is coupled to the accelerometer to transmit tothe remote server other device an inclination signal derived from anoutput of the accelerometer.
 3. The adherent device of claim 1, whereinthe adherent patch is disposable.
 4. The adherent device of claim 1,wherein the adherent patch further comprises a respective gel disposedover a contact surface of each of the plurality of electrodes toelectrically connect the respective electrode to the skin of thepatient.
 5. The adherent device of claim 4, wherein the adherent patchfurther comprises a gel cover positioned over the breathable tape toinhibit a flow of the gel through the breathable tape and wherein theelectronics module is located over the gel cover such that the gel coveris disposed between the breathable tape and the electronics module. 6.The adherent device of claim 1, further comprising a breathable coverdisposed over the electronics module.
 7. The adherent device of claim 1,wherein the plurality of electrodes comprises at least four electrodesarranged linearly, the four electrodes comprising two end electrodes andtwo inner electrodes, and wherein the distance between the innerelectrodes is larger than the distance between either end electrode andits adjacent inner electrode.
 8. An adherent device to monitor a patientfor an extended period, the device comprising: a first adherent patchcomprising a breathable tape with an adhesive coating to adhere thebreathable tape to a skin of the patient, the adherent patch alsocomprising a plurality of electrodes affixed to the breathable tape andcapable of electrically coupling to the skin of the patient; and anelectronics module comprising impedance circuitry coupled to at leasttwo of the plurality of electrodes and electrocardiogram circuitrycoupled to at least two of the plurality of electrodes, the electronicsmodule also comprising wireless communications circuitry coupled to theimpedance circuitry and to the electrocardiogram circuitry to transmitto a remote server another device a hydration signal derived from anoutput of the impedance circuitry and an electrocardiogram signalderived from an output of the electrocardiogram circuitry; wherein theelectronics module is coupled to the breathable tape to support theelectronics module when the tape is adhered to the patient; and whereinthe electronics module is separable from the adherent patch such thatthe electronics module can be reused with a second adherent patch toprovide monitoring for an extended period; and wherein the electronicsmodule is coupled to the plurality of electrodes using a flexibleconnection; wherein the adherent patch further comprises a respectivegel disposed over a contact surface of each of the plurality ofelectrodes to electrically connect the respective electrode to the skinof the patient; and wherein the adherent patch further comprises a gelcover positioned over the breathable tape to inhibit a flow of the gelthrough the breathable tape, and wherein the electronics module islocated over the gel cover such that the gel cover is disposed betweenthe breathable tape and the electronics module, wherein the gel cover isconfigured to inhibit transmission of liquid water and permittransmission of moisture vapor.
 9. The adherent device of claim 8,wherein the electronics module further comprises an accelerometer, andwherein the wireless communications circuitry is coupled to theaccelerometer to transmit to the remote server other device aninclination signal derived from an output of the accelerometer.
 10. Theadherent device of claim 8, wherein the adherent patch is disposable.11. The adherent device of claim 8, wherein the plurality of electrodescomprises at least four electrodes arranged linearly, the fourelectrodes comprising two end electrodes and two inner electrodes, andwherein the distance between the inner electrodes is larger than thedistance between either end electrode and its adjacent inner electrode.12. A system for monitoring a patient, the system comprising: anadherent device comprising an adherent patch and an electronics module;and an intermediate device; wherein the adherent patch comprises abreathable tape with an adhesive coating to adhere the breathable tapeto a skin of the patient, and a plurality of electrodes affixed to thebreathable tape and capable of electrically coupling to the skin of thepatient; wherein the electronics module is coupled to the breathabletape to support the electronics module when the tape is adhered to thepatient; wherein the electronics module is separable from the adherentpatch such that the electronics module can be reused with a secondadherent patch to provide monitoring for an extended period; wherein theelectronics module comprises electrocardiogram circuitry coupled to atleast two of the plurality of electrodes and impedance circuitry coupledto at least two of the plurality of electrodes, and also compriseswireless communications circuitry coupled to the electrocardiogramcircuitry and to the impedance circuitry to transmit to the intermediatedevice an electrocardiogram signal derived from an output of theelectrocardiogram circuitry and a hydration signal derived from anoutput of the impedance circuitry; wherein the adherent patch furthercomprises a respective gel disposed over a contact surface of each ofthe plurality of electrodes to electrically connect the respectiveelectrode to the skin of the patient; wherein the adherent patch furthercomprises a gel cover positioned over the breathable tape to inhibit aflow of the gel through the breathable tape and wherein the electronicsmodule is located over the gel cover such that the gel cover is disposedbetween the breathable tape and the electronics module, wherein the gelcover is configured to inhibit transmission of liquid water and permittransmission of moisture vapor; and wherein the intermediate devicetransmits the electrocardiogram signal and the hydration signal to aremote server.
 13. A method of monitoring a patient, the methodcomprising: providing an adherent device comprising a first adherentpatch and an electronics module, wherein the first adherent patchcomprises a breathable tape with an adhesive coating to adhere thebreathable tape to a skin of the patient and the first adherent patchcomprises a plurality of electrodes affixed to the breathable tape andcapable of electrically coupling to the skin of the patient, wherein theelectronics module is coupled to the breathable tape to support theelectronics module when the tape is adhered to the patient, and whereinthe electronics module comprises electrocardiogram circuitry coupled toat least two of the plurality of electrodes and impedance circuitrycoupled to at least two of the plurality of electrodes, and alsocomprises wireless communications circuitry coupled to theelectrocardiogram circuitry and to the impedance circuitry to transmitto a remote server another device an electrocardiogram signal derivedfrom an output of the electrocardiogram circuitry and a hydration signalderived from an output of the impedance circuitry, wherein the adherentpatch further comprises a respective gel disposed over a contact surfaceof each of the plurality of electrodes to electrically connect therespective electrode to the skin of the patient, and wherein theadherent patch further comprises a gel cover positioned over thebreathable tape to inhibit a flow of the gel through the breathable tapeand wherein the electronics module is located over the gel cover suchthat the gel cover is disposed between the breathable tape and theelectronics module, wherein the gel cover is configured to inhibittransmission of liquid water and permit transmission of moisture vapor;adhering the adherent device to the patient; monitoring the patient fora first period of time, including transmitting the electrocardiogramsignal and the hydration signal to the remote server the other device;separating the first adherent patch from the electronics module;providing a second adherent patch like the first; coupling theelectronics module to the second adherent patch and adhering the secondadherent patch to the skin of the patient; and monitoring the patientfor a second period of time, including transmitting theelectrocardiogram signal and the hydration signal to the remote serverother device.
 14. The method of claim 13, further comprising disposingof the first adherent patch.
 15. The adherent device of claim 1, whereinthe gel cover is connected to the breathable tape.
 16. The adherentdevice of claim 1, wherein the electronics module comprises a printedcircuit board connected to one or more of the electrocardiogramcircuitry, the impedance circuitry, or the wireless communicationcircuitry, and wherein the gel cover is disposed between the breathabletape and the printed circuit board.
 17. The adherent device of claim 1,wherein the breathable tape has a first porosity, and the gel cover hasa second porosity less than the first porosity.
 18. The adherent deviceof claim 1, wherein the electronics module is configured to determine atleast one of heart rate variability or heart rate turbulence based onthe electrocardiogram signal.
 19. The adherent device of claim 7,wherein the at least four electrodes comprises four electrodes arrangedlinearly, the four electrodes comprising two end electrodes and twoinner electrodes, and wherein the distance between the inner electrodesis larger than the distance between either end electrode and itsadjacent inner electrode.
 20. The adherent device of claim 8, whereinthe gel cover is connected to the breathable tape.
 21. The adherentdevice of claim 8, wherein the electronics module comprises a printedcircuit board connected to one or more of the electrocardiogramcircuitry, the impedance circuitry, or the wireless communicationcircuitry, and wherein the gel cover is disposed between the breathabletape and the printed circuit board.
 22. The adherent device of claim 8,wherein the breathable tape has a first porosity, and the gel cover hasa second porosity less than the first porosity.
 23. The adherent deviceof claim 8, wherein the electronics module is configured to determine atleast one of heart rate variability or heart rate turbulence based onthe electrocardiogram signal.
 24. The adherent device of claim 11,wherein the at least four electrodes comprises four electrodes arrangedlinearly, the four electrodes comprising two end electrodes and twoinner electrodes, and wherein the distance between the inner electrodesis larger than the distance between either end electrode and itsadjacent inner electrode.
 25. The system of claim 12, wherein the gelcover is connected to the breathable tape.
 26. The system of claim 12,wherein the electronics module comprises a printed circuit boardconnected to one or more of the electrocardiogram circuitry, theimpedance circuitry, or the wireless communication circuitry, andwherein the gel cover is disposed between the breathable tape and theprinted circuit board.
 27. The system of claim 12, wherein thebreathable tape has a first porosity, and the gel cover has a secondporosity less than the first porosity.
 28. The system of claim 12,wherein the electronics module is configured to determine at least oneof heart rate variability or heart rate turbulence based on theelectrocardiogram signal.
 29. A device configured to monitor a patient,the device comprising: a patch comprising a breathable layer configuredto contact to a skin of the patient, the patch also comprising aplurality of electrodes affixed to the breathable layer and configuredto electrically couple to the skin of the patient; and an electronicsmodule configured to be coupled to the breathable layer, and to derivean electrocardiogram signal and a hydration signal via plurality ofelectrodes; wherein the patch further comprises a respective geldisposed over a contact surface of each of the plurality of electrodesto electrically connect the respective electrode to the skin of thepatient; and wherein the patch further comprises a gel cover positionedover the breathable layer to inhibit a flow of the gel through thebreathable layer, and wherein the electronics module is located over thegel cover such that the gel cover is disposed between the breathablelayer and the electronics module, wherein the gel cover is configured toinhibit transmission of liquid water and permit transmission of moisturevapor.